Sanding jig



Dec. 24, 1957 R. E. UNZICKER SANDING JIG Filed 001:. 1, 1956 IN V EN TOR.

Roamr UIYZ/GKER BY a: e

Un t ws atfl 'fl SANDING JIG Robert E. Unzicker, Cedar Rapids, Iowa, assignor to Collins Radio Company, Cedar Rapids, Iowa, a corporation of Iowa Application October 1, 1956, Serial No. 613,305

3 Claims. (Cl. 51-217) This invention relates to workpiece holders and more particularly to holders for thin, flat pieces of various shapes.

Prior art methods of sanding small pieces involved holding each piece against a stop or on .pins, sanding it individually, and then turning it by hand and sanding the other side. Necessarily, the sanding rate under these conditions is quite slow.

Accordingly, it is an object of this invention to provide workpiece holders which are capable of holding small, thin pieces of stock and which permit rapid sanding of such parts.

It is an object of this invention to provide holders f small, thin pieces which facilitate rapid handling thereof.

It is a further object of this invention to provide a sanding jig which speeds up production.

It is a feature of jigs made under this invention that they are adjustable, permitting a variety of small pieces to be sanded thereon.

It is a further feature of this invention that round shapes which ordinarily have to be set on pins can be sanded on jigs made according to the invention with a resulting increase in production.

Further objects, features, and advantages of the invention Will become apparent from the following description and claims when read in conjunction with the drawing in which:

Figure 1 shows the invention related to holding circular pieces for sanding,

Figure 2 shows another form of the invention for holding a plurality of small pieces, and

Figure 3 shows the form of Figure 2 closed.

In Figure 1 a base is provided with a work surface 11. On this work surface a pivoted, movable stop 12 is mounted close to one edge of the base 10. The pivoted stop swings about pivot 13. The main portion of the pivoted stop is straight and rectangular in cross section. At the end opposite the pivot the stop is shaped in the form of a handle 14 and projects beyond the base 10 for its easy manipulation. A hole 15 is provided in the handle portion extending over the edge of base 10. On the same edge of the base near the opposite side a pin 16 is provided.

Between hole 15 and pin 16 a tension spring 17 is mounted. Protecting spring 17 is a shield 18 which is shown covering only a portion thereof but which extends to cover the full length of the spring and to provide a no-workpiece stop for the pivoted stop.

Base 10 is provided with a number of pairs of holes 20. Over one of these pairs of holes a fixed stop 21 is positioned. Fixed stop 21 has pins 22 projecting from it which enter said pair of holes. The fixed stop 21 is set at such a distance from the pivoted stop 12 that when a workpiece is clamped between the two, they will be parallel. A workpiece 24 is shown held between the two stops.

While this jig will hold any shape workpiece, it is par ticularly adaptable to holding round shapes which, prior 2 to this time, had to be sanded on pins to prevent the pieces from turning while being sanded.

In use, the jig is laid flat on the sanding table. The handle 14 is moved relative to the base 10 stretching spring 17. A workpiece such as the round disc 24 is laid flat on the base between the two stops. Handle 14 is released, permitting the spring tension to clamp the workpiece between the two stops. The jig and piece are then moved under the sanding belt and the belt is pressed onto the workpiece for the sanding operation. Removal of the workpiece etc. is a reverse of the loading procedure. The old work rate with pins for holding the round pieces was considered acceptable at pieces per day. Withthis jig, approximately 400 pieces per hour can be sanded with as good a quality of workmanship.

In Figure 2, two flat bases 30 and 31 are provided. Bases 30 and 31 are hinged together by hinge bars 32. These hinge bars are pivoted at each end by pivot 33 in block 30 and pivot 34 in base 31. A latch 36 is mounted on base 31 by a bracket 37. A cooperating latch pin 38 is mounted on base 30.

Stops are provided on the inside meeting surfaces of the bases. On base 30 an L-shaped stop 40 is mounted. This L-shape extends along two adjoining sides of the base and is slightly thinner than the thinnest workpiece expected. This L-shaped stop is fixed on base 30 with its legs adjacent a side running across the axis of the hinge, and a side parallel to but opposite the hinge side of the base. On base 31 a fixed stop 41 meets and closes on the leg of the L-shaped fixed stop 40 which is perpendicular to the hinge axis. A series of holes 42 are provided for mounting adjustable stop 43. Adjustable stop 43 is secured to base 31 by means of pins 44 inserted into holes 42.

Stop 43 is parallel to the axis of the hinges and during adjustment is maintained parallel thereto. A series of rectangular workpieces 45 are shown lying on base 30. The adjustment of stop 43 is related to the length of the workpieces on a line shown as double-headed arrow 46 of the workpieces 45. Stop 43 is positioned towards or away from the axis of the hinges such as that when base 31 is folded over onto the top of the workpieces 45, stop 43 comes just next to the hinge side of the workpieces. This encloses them between the fixed L-shaped stop on base 30 and the movable stop 43 on base 31 to prevent motion transverse to the hinge axis.

In operation, the jig of Figure 2 is loaded with workpieces 45 as shown. The jig is laid flat on the sanding table, under the sanding belt, and the sanding belt pressed down onto the workpieces for the sanding operation.

After these pieces are sanded on one side, the jig is removed from under the sanding belt, base 31 is closed over onto base 30, as seen in Figure 3, latch 36 is locked onto latch pin 38, and the jig turned over on an axis parallel to the hinge axis, so that base 31 is now underneath. The latch is then released and base 30 lifted up off of the workpieces. As a result of proper adjustment of stop 43 to the length of the workpiece, the workpieces will now be in area 47 on base 31 and will be against. the two stops 41 and 43.

The jig is then put under the sanding belt a second time and the belt is pressed down onto the workpieces to complete the sanding operation on the second side of the workpieces. The jig is then removed from the machine, the workpieces are spilled oflf into a receiving bin of some nature and the jig is ready for a new load of workpieces.

It will be noted that the workpieces are handled once in orienting and loading them onto the base 30. The pieces are turned over in one motion and are then unloaded after the second side is sanded without the operator touching them. This permits a very high piece-sanding Patented Dec. 24, 1957 rate which makes the pieces too hot to touch as to turning them over by hand for sanding the second side. With the turnover jig the operator does not touch a hot workpiece and therefore does not burn his fingers by handling a hot piece.

Although this invention has been described with respect to particular embodiments thereof, it is not to be so limited because changes and modifications may be made therein which are within the full intended scope of the invention as defined by the appended claims.

I claim:

1.A sanding jig comprising two bases, hinge means having an axis, said hinge means joining said two bases at one edge, an L-shaped stop fixed to one of said bases, said L extending away from said axis at one edge and along said axis and an edge of the base opposite said axis from said hinge means, adjustable stop means mounted on said other base, said adjustable stop on said other base being so positioned that the stop on the two bases enclose workpieces such that the two bases-may be closed together and turned over to turn over the workpieces.

2. A holder for a thin, flat workpiece having a desired length dimension comprising a base, first stop means fixed to said base, hinge means, a cover base, said cover base being mounted by said hinge means on said base so that the base and the cover base may lie in parallel planes while open or closed, second stop means, said second stop means being mounted on said cover base a desired dimension apart from said first stop means when said cover base and base are closed together.

3. A workpiece holder comprising a pair of bases, hinge means for relating said pair of bases as pages in a book, stop means on each base, said stop means being related such that closing said bases together encloses a workpiece between stops, whereby the assembly may be turned over to expose the reverse side of said workpiece.

References Cited in the file of this patent UNITED STATES PATENTS 497,115 Brockrnan May 9, 1893 1,065,994 Williams July 1, 1913 1,904,274 Crowley Apr. 18, 1933 2,277,559 Pizzino Mar. 24, 1942 2,305,945 Williams et al. Dec. 22, 1942 

